Fuel oil composition



United States No Drawing. Filed July 20, 1960, Ser. No. 46,109 9 Claims.(Ci. 44--7S) This invention relates to novel corrosion and/ or rustinhibitors particularly adapted for use in preventing corrosion ofmetals especially iron, steel and ferrous alloys by liquids containingcorrosive compounds such as, for example, petroleum fuel oil and to themethod of preventing such corrosion.

The rusting of steel used in the transportation and storage of petroleumfuel oils has always presented a serious problem. The presence ofsediment and rust as a result of corrosion and the carry-over of thesediment into the fuel burning installations presents a seriousoperating problem. In addition to the possibility of storage tankrusting through with the consequent loss of fuel oil, there is theadditional danger that the furnace filters and furnace fuel lines maybecome clogged, thus causing the failure of the heating system.

The problem of corrosion or rusting is associated with the presence ofmoisture in the oil products caused by entrainment, condensation andsolution. In most cases, the problem is accentuated by the presence of aseparate water phase. Thus, in the storage and bulk shipment of fueloil, it is common practice to maintain a water layer as tank bottoms.Even where a separate water layer is not maintained as tank bottoms, aseparate water phase may be formed by repeated condensation of moistureassociated with tank breathing or the repeated expansion and contractionof the bulk due to temperature changes unless special precautions aretaken. Complete protection against rusting, therefore, requires acorrosion inhibitor which is effective in both the oil and water phase.

It is an object of the present invention to provide a corrosion and/orrust inhibitor adapted for use in preventing the corrosion and/ orrusting of metals by liquids containing corrosive compounds associatedwith oleaginous materials such as petroleum fuel oils. It is a furtherobject of this invention to provide a normally liquid nonlubricatinghydrocarbon fuel oil composition having improved rust inhibitingproperties for the protection of metal surfaces of oil storage and/orhandling equipment whether metal surfaces be exposed to the oil or tothe Water phase. Other objects and advantages of the invention willbecome apparent from the following description thereof.

I have now discovered certain new corrosion inhibitors which findutility as a corrosion inhibitor for fuel oils. The corrosion inhibitoris represented by the following structural formula:

ate 1 3,llb,l2 Patented Dec. 31, 1963 "ice wherein R is the group havingthe formula:

OOOH R 0 l R is selected from the class consisting of hydrogen andmethyl, and R is an aliphatic hydrocarbon group having from 6 to 22 andpreferably from about 12 to 18 carbon atoms. R R and R preferably areopen chain aliphatic hydrocarbon groups and advantageously may containfrom 0 to 2 unsaturated linkages; preferably they are saturated.

The corrosion inhibitors of this invention may be used to form a fueloil composition containing a major proportion of a distillate fuel oiland a small or minor amount of the corrosion inhibitor. Such distillatefuel oil compositions may comprise a distillate fuel oil containing fromabout 0.0001 to about 5 weight percent and preferably from about 0.001to about 0.05 Weight percent of the corrosion inhibitor. The corrosioninhibitor may also be formulated as an addition agent concentrate in asuitable organic solvent as more particularly described below. Thisconcentrate may be used by further dilution with the distillate fuel oilto form the distillate fuel oil composition. The corrosion inhibitors ofthe present invention are advantageously oil-soluble.

The corrosion inhibitors of this invention may be prepared by reactingthe corresponding hydroxyalkyl amine in the presence of an inert solventwith trirnellitic anhydride. The reaction may be carried out in thepresence of a solvent such as benzene, ethanol, n-butanol, isobutanol,xylene, etc. An acceptable temperature for the reaction may be in therange of from about 50 F. to about 200 F. although higher or lowertemperatures may be used.

Examples of specific materials which may be used in accordance with thehereinabove mentioned method and formula are illustrated in Table I.

The following procedures illustrate the method of preparing specificexamples set forth in Table I.

solvent was removed by vacuum distillation thus leaving 8.5 g. ofN,N,N'-tri-[2-(2,5-dicarboxybenzoxy) propyl1-N-ta1low-1,3-propanediamine having the formula:

Procedure A I? A mixture of 21.28 g. of N,N,N'-tri (Z-hydroxy) ethyl- TN-tallow-1,3-propanediamine, 23.04 g. of trimellitic ann, hydride, and250 ml. of acetone solvent were placed in (IJHZ COOH a reactor. Thereactor was heated to the reflux temperatture of the acetone andrefluxed for a period of 3 hours. (3H2 H 46 g. ofN,N,N-tri-[2-(2,4-dicarboxybenzoxy) ethyl]-N'- C0011tallow-l,3-propanediamine having the following formula I- wererecovered: (30 OH 2 (I311: C H2 I CH2 0 Procedure B The corrosioninhibitors defined herein, such as those prepared as described above aswell as those set forth in the above examples are usable in minoramounts from about 0.0001 to about 5 weight percent and preferably fromabout 0.001 to about 0.05 weight percent in distillate fuel oils.

The distillate fuel oil may be virgin or cracked petroleum distillatefuel oil. The fuel oil may boil in the range of from about 200 to about750 F., and preferably in the range of 350 to 650 F. The distillate fueloil may contain or consist of cracked components such as, for example,those derived from cycle oils or cycle oil cuts boiling heavier thangasoline, usually in the range of from about 450 to 750 F. and may bederived by catalytic or thermal cracking. The distillate oil may containother components such as addition agents used for a particular functionsuch as, for example, pour point depressants, combustion improvers, orthe like.

The distillate fuel oil is preferably a heating oil in which thecorrosion inhibitors of this invention are used in accordance herewith.These oils are intended for use by burning to obtain heat such as isintended for furnace or heater fuel use as opposed to internalcombustion C O OH engine fuel wherein the explosiveness of the fuel in acom- 0113 0 bustion chamber is of prime importance. Examples of hh' '1 h1 'd 1r1 R N CH2CH 0 C COOH 811C eating 01 S are a eavy industna IfiSlua L16 (e.g. L 2 Bunker C), a heater oil fraction, :1 gas oil, a furnaceoil,

Procedure C kerosene, or any other light oil intended for furnace orheater fuel use.

The rust inhibiting properties of the above described compositions wereevaluated by the following test:

INDIANA CONDUCTOMETRIC TEST (STATIC) This test, which quantitativelymeasures corrosion rates, depends upon the measurement of the change inelectrical resistance of a steel test strip immersed in the corrosivemedium. The change in resistance is simply related to the decrease inthe thickness of the test specimen caused by corrosion. In the test,specimen holders are designed to make electrical connections to twosteel strips suspended in large glass test tubes. A mixture is preparedusing six parts of fuel oil containing the rust inhibitor and four partsdouble distilled water. The corrosion test strips are first immersed inthe fuel oil containing the rust inhibitor for a period of one-half hourand subsequently suspended in the mixture such that approximatelyone-half of the specimen is above the oilwater interface and theremaining half of the specimen is below the oil-water interface. Thestrips are maintained in the mixture for a period of 24 hours at atemperature of 25 C. The corrosion rates are calculated on a quantativebasis from the observed change in electrical resistance.

The data obtained by subjecting the products of this invention to theabove test are tabulated in the following table and demonstrate theeffectiveness of the herein de scribed products in inhibiting rust infuel oil compositions.

Note-The above test conditions used virgin gas oil and double distilledwater for the blank and test samples.

The corrosion inhibitors of the present invention may, for convenience,be prepared as an addition agent concentrate. Accordingly, the corrosioninhibitor is prepared in or dissolved in a suitable organic solventtherefor in amounts greater than and preferably from about to about 65%.The solvent, in such concentrate, may conveniently be present in amountsof from about to about 75%. The organic solvent preferably boils withinthe range of from about 100 F. to about 700 F. For the preferred heatingoil use, the organic solvents may advantageously be hydrocarbonsolvents, for example, petroleum, petroleum fractions, such as naphtha,heater oil, mineral spirits and the like, because of their clean burningproperties. The solvents selected should, of course, be selected withregard to beneficial or adverse affects it may have on the ultimate fueloil composition. Thus, the solvent should preferably burn withoutleaving a residue and should be non-corrosive with regard to metal, andespecially ferrous metals. Other desirable properties are obvious fromthe intended use of the solvent.

The terms coco, soybean, tallow, and the like as used herein denote thatthe group so identified is derived from a particular source. The cocogroups are derived rom rrixtures of coco fatty acids; the soybean groupsare derived from soybean fatty acids; the tallow groups are derived fromtallow fatty acids. Such coco, soybean and tallow fatty acids arederived from coconut, soybean and tallow oils and are marketedcommercially. Each such group is usually a mixture of carbon chainsdiffering slightly in length and/ or configuration. For example, thetallow groups are a mixture of C to C groups predominating in stearyland palmityl groups. The groups are wel known in the additive art.

Wherever percentages are given herein, weight percentages are intendedunless otherwise indicated.

t is evident from the foregoing that I have provided new and usefulcorrosion inhibitors for distillate fuel oils and particularly indistillate heating oils.

1 claim:

1. A distillate fuel oil composition comprising a major proportion of ahydrocarbon oil fraction in the fuel oil distillation range and fromabout 0.0O01% to about 5% of a compound having the general formula:

a wherein R is the group having the formula:

COOH B4 II wherein R is selected from the class consisting of R and analiphatic hydrocarbon group having from 6 to 22 carbon atoms and R isselected from the class consisting of an aliphatic hydrocarbon grouphaving from 6 to 22 carbon atoms and the group having the formula:

COOH 4 wherein R is selected from the class consisting of R and analiphatic hydrocarbon group having from 12 to 18 carbon atoms and R isselected from the class consisting of an aliphatic hydrocarbon grouphaving from 12 to 18 carbon atoms and the group having the formula:

wherein R is selected from the class consisting of R and a saturatedaliphatic hydrocarbon group having from about 12 to about 18 carbonatoms, R is selected from the class consisting of a saturated aliphatichydrocarbon group having from about 12 to about 18 carbon atoms and thegroup having the formula:

wherein R is selected from the class consisting of hydrogen and methyl,and R is a saturated aliphatic hydrocarbon group having from 12 to about18 carbon atoms.

4. A fuel oil composition comprising a major proportion of a hydrocarbonoil fraction in the fuel oil distilla- 7 tion range from about 0.0001 toabout 5% by weight of a N,N,N' tri [2 (2,5 dicarboxybenzoxy)propyl] Ntallow-1,3 -prop-anediamine.

5. A fuel oil composition comprising a major proportion of a hydrocarbonoil fraction in the fuel oil distillation range from about 0.001 to0.05% by weight of a N,N,N' tri [2 (2,5 dicarboxybenzoxy)propyl] Ntallow-1,3 -propanediamine.

6. A fuel oil composition comprising a major proportion of a hydrocarbonoil fraction in the fuel oil distillation range from about 00001 to 5%by weight of a N,N-di

[2- 2,4-dicarboxybenzoxy propyl] -tallow amine.

7. A fuel oil composition comprising a major proportion of a hydrocarbonoil fraction in the fuel oil distillation range from about 0.001 to0.05% by weight of a 15 N,N-di [2- 2,4-dicarboxybenzoxy propyl] -tallowamine.

10 tallow-1,3-propanediamine.

References Cited in the file of this patent UNITED STATES PATENTS

1. A DISTILLATE FUEL OIL COMPOSITION COMPRISING A MAJOR PROPORTION OFHYDROCARBON OIL FRACTION IN THE FUEL OIL DISTILLATION RANGE AND FROMABOUT 0.0001% TO ABOUT 5% OF A COMPOUND HAVING THE GENERAL FORMULA: